The unemployment rate dropped for all the right reasons in April, but a broader rate that includes underemployed and discouraged workers rose, underlining concerns about the types of jobs being created.

The drop in the main unemployment rate was driven by a jump in the number of people who count as employed, even as the number of unemployed declined. The unemployment rate is based on the number of unemployed — people who are without jobs, who are available to work and who have actively sought work in the prior four weeks. The “actively looking for work” definition is fairly broad, including people who contacted an employer, employment agency, job center or friends; sent out resumes or filled out applications; or answered or placed ads, among other things. The unemployment rate is calculated by dividing the number of unemployed by the total number of people in the labor force.

This month the number of unemployed dropped by more than 80,000, even as more people entered the labor force. Meanwhile, the number of employed workers jumped by 293,000. The total labor force increased by 210,000, leaving the labor force participation rate unchanged at 63.3%. The steady rate is a positive sign that people are encouraged enough to look for work, and raises hope that more long-term unemployed aren’t just dropping out.

But there was an area of concern in the report as a broader rate, known as the “U-6″ for its data classification by the Labor Department, increased to 13.9% from 13.8% a month earlier. That includes everyone in the official rate plus “marginally attached workers” — those who are neither working nor looking for work, but say they want a job and have looked for work recently; and people who are employed part-time for economic reasons, meaning they want full-time work but took a part-time schedule instead because that’s all they could find.

In April, the rate ticked up as the number of workers who are part-time but want full-time work increased. That came even as the numbers of hours worked also dropped this month for all workers. This raises the question about the kinds of jobs being created, and whether they can support a faster recovery.

To be sure, a 278,000 jump in the part-time for economic reasons category followed a big drop the month before. But there still are nearly 8 million people in the U.S. who want a better job, while more than 11.5 million remain unemployed.

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